$border($border-width = 1px 0 0 0, $border-color = #ccc, $border-style = solid, $radius = 0)
  // 为边框位置提供定位参考
  position: relative;
  if $border-width == null
      $border-width: 0;

  border-radius: $radius;
  &::after
    // 用以解决边框layer遮盖内容
    pointer-events: none;
    position: absolute;
    z-index: 999;
    top: 0;
    left: 0;
    // fix当元素宽度出现小数时，边框可能显示不全的问题
    // overflow: hidden;
    content: "\0020";
    border-color: $border-color;
    border-style: $border-style;
    border-width: $border-width;

    @media all and (max--moz-device-pixel-ratio: 1.49),
      (-webkit-max-device-pixel-ratio: 1.49),
      (max-device-pixel-ratio: 1.49),
      (max-resolution: 143dpi),
      (max-resolution: 1.49dppx)
        width: 100%;
        height: 100%;
        if $radius != 0
          border-radius: $radius;
          
    @media all and (min--moz-device-pixel-ratio: 1.5) and (max--moz-device-pixel-ratio: 2.49),
      (-webkit-min-device-pixel-ratio: 1.5) and (-webkit-max-device-pixel-ratio: 2.49),
      (min-device-pixel-ratio: 1.5) and (max-device-pixel-ratio: 2.49),
      (min-resolution: 144dpi) and (max-resolution: 239dpi),
      (min-resolution: 1.5dppx) and (max-resolution: 2.49dppx)
        width: 200%;
        height: 200%;
        transform: scale(0.5)
        if $radius != 0
          border-radius: $radius * 2;
      
    @media all and (min--moz-device-pixel-ratio: 2.5),
      (-webkit-min-device-pixel-ratio: 2.5),
      (min-device-pixel-ratio: 2.5),
      (min-resolution: 240dpi),
      (min-resolution: 2.5dppx)
        width: 300%;
        height: 300%;
        transform: scale(0.333333)
        if $radius != 0
          border-radius: $radius * 3;
        
    transform-origin 0 0